Self-expanding nerve cuff electrode

ABSTRACT

An electrode lead comprises an elongated lead body, at least one lead connector terminal affixed to the proximal end of the lead body, and an electrically insulative cuff body affixed to the distal end of the lead body. The cuff body is configured for being circumferentially disposed around a nerve. The cuff body comprises cutouts, slits, a wrinkled portion, a thin stretchable portion, and/or a serpentine strap, which increases that increase the expandability of the cuff body when disposed around the nerve. The electrode lead further comprises at least one electrode contact affixed to the cuff body, and at least one electrical conductor extending through the lead body between the at least one lead connector terminal and the electrode contact(s). If the cuff body comprises cutouts or slits, the electrode lead can further comprise a thin stretchable film affixed to the cuff body over cutouts or slits.

RELATED APPLICATION DATA

The present application is a continuation of U.S. patent applicationSer. No. 15/967,468, filed Apr. 30, 2018 (now U.S. Pat. No. 10,981,000),which claims the benefit of priority to U.S. Provisional ApplicationSer. No. 62/500,091, filed on May 2, 2017 and claims the benefit ofpriority to U.S. Provisional Application Ser. No. 62/500,080, filed onMay 2, 2017. The contents of the aforementioned patent applications arehereby expressly incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention generally relates to implantable neurostimulationleads, and specifically relates to implantable nerve cuff electrodesthat can be used to stimulate nerves to treat ailments, such asobstructive sleep apnea (OSA).

BACKGROUND OF THE INVENTION

Obstructive sleep apnea (OSA) is a common disorder in which the upperairway of a patient can become obstructed (apnea) or partiallyobstructed (hypopnea) during sleep. It is highly prevalent, affecting5%-10% of the adult population in the United States, and has seriouseffects and comorbidities, such as daytime sleepiness, snoring, poorsleep quality, and an increased risk of cardiovascular disease and motorvehicle accidents. Conventional treatments of OSA include usingcontinuous positive airway pressure (CPAP) techniques or performingupper airway surgery. However, due to discomfort, CPAP has a lowadherence rate over time, thereby limiting its effectiveness.Alternatively, upper airway surgery is painful and requires a prolongedrecovery period, and therefore is used as a last resort to the treatmentof OSA, reserved for only extreme cases.

In response to disadvantages of the conventional techniques for treatingOSA, a new approach involves stimulating the hypoglossal nerve, whichinnervates the upper airway muscle, to increase the patency of the upperairway of the patient, thereby preventing or minimizing the onset ofOSA. For example, one such neurostimulation system for treating OSAincludes a neurostimulator device that stimulates one or more branchesof the hypoglossal nerve via electrodes that are implanted at thehypoglossal nerve.

It is desirable that any electrode implanted in contact with a nerve,such as the hypoglossal nerve, continually remain in firm contact withsuch nerve to maximize the effectiveness of the stimulation regimen.However, certain regions of the patient, such as the neck region, aresubject to various dynamic forces that may dislodge or otherwise causean electrode to migrate from or otherwise temporarily move from itsoriginal or desired implantation site, which may have deleterious effecton the stimulation regimen, and thus, the treatment of the ailment, suchas OSA.

A reliable solution to this migration problem is to use a nerve cuffelectrode device, which can be circumferentially placed around the nerveto deliver effective electrical stimulation to that nerve. This approachprovides a more effective anchoring means that keeps the electrode infirm contact with the nerve to which it is attached even when theimplantation site is subject to dynamic forces. However, due to thesurgical process used to install the nerve cuff electrode around thenerve, the trauma experienced by the nerve will result in nerveswelling, which may expand the circumference of the nerve by as much as150%.

A conventional approach to securing a nerve cuff electrode to a nerveinvolves placing the cuff, which is generally C-shaped nerve cuff,around the nerve and securing the cuff using a locking mechanism, suchas sutures or other locking means, thereby preventing the nerve cufffrom being dislodged. However, the tightly secured cuff electrode mayconstrict the blood flow to the nerve, essentially strangling it,resulting in damage and even death to the nerve. Although the diameterof the cuff electrode may be sized to accommodate the swelling of thenerve, once the nerve swelling subsides, the cuff electrode needs toreduce its lumen size to form fit around the nerve. The major problemwith conventional cuff electrodes is that having a fixed lumen sizecannot accommodate changes in the diameter of a nerve which can swelland then reduces its diameter post swelling.

There, thus, remains a need for a nerve cuff electrode design that doesnot cause nerve constriction when the nerve swells and yet, is able toprovide effective nerve stimulation when the nerve stops swelling andthe nerve diameter decreases to a size that is closer to original size.

SUMMARY OF THE INVENTION

In accordance with the present invention, an electrode lead comprises anelongated lead body having a proximal end and a distal end, at least onelead connector terminal affixed to the proximal end of the lead body,and a biologically compatible, elastic, electrically insulative cuffbody affixed to the distal end of the lead body, at least one electrodecontact affixed to the cuff body, and at least one electrical conductorextending through the lead body between the lead connector terminal(s)and the electrode contact(s). The cuff body is configured for beingcircumferentially disposed around a nerve. The cuff body may be, e.g.,composed of silicone, and may have a thickness less than 1 mm. Theelectrode contact(s) may be configured for being on an inner surface ofthe cuff body when disposed around the nerve. The electrode lead mayfurther comprise a locking feature configured for firmly securing thecuff body around the nerve.

In accordance with a first aspect of the present invention, the cuffbody comprises a plurality of cutouts that increase the expandability ofthe cuff body when disposed around the nerve. The cutouts may for aplurality of struts (e.g., chevron-shaped struts, which may bealternately angled in opposite directions, or U-shaped struts). In oneembodiment, the cuff body has opposing first and second regions, and thecutouts are only in the first region of the cuff body, and the electrodecontact(s) are affixed to the second region of the cuff body.

In accordance with a second aspect of the present invention, the cuffbody has opposing first and second edges, and comprises a plurality ofslits divided into a first set of slits that extend from the first edgetowards a center of the cuff body, and a second set of slits that extendfrom the second edge towards the center of the cuff body, therebyincreasing the expandability of the cuff body when disposed around anerve. In one embodiment, the first and second sets of slits alternatewith each other, and may extend past a centerline between the first andsecond edges of the cuff body. In another embodiment, the first andsecond sets of slits are aligned with each other, but do not extend pasta centerline between the first and second edges of the cuff body. Inthis case, the cuff body may further comprise a third set of slitsextending through the centerline, but not extending to the first andsecond edges of the cuff body. The third set of slits and first andsecond sets of slits may alternate with each other. The cuff body mayoptionally comprise a plurality of circular relief cutouts disposed atthe ends of the slits opposite the respective first and second edgesfrom which the slits extend. In one embodiment, the cuff body hasopposing first and second regions, the slits are only in the firstregion of the cuff body, and the electrode contact(s) are affixed to thesecond region of the cuff body.

In accordance with a third aspect of the present invention, the cuffbody comprises an unwrinkled portion and a wrinkled portion, therebyincreasing the expandability of the cuff body when disposed around anerve. The unwrinkled portion and the wrinkled portion may have the samethickness. In one embodiment, the cuff body comprises first and secondregions opposite to each other, the unwrinkled portion is incorporatedinto the first region, and the wrinkled portion is incorporated into thesecond region, such that the wrinkled portion is configured foroverlapping the unwrinkled portion when the cuff body is disposed aroundthe nerve. The electrode contact(s) may be affixed to the second regionof the cuff body.

In accordance with a fourth aspect of the present invention, the cuffbody comprises a thicker portion and a thinner portion, therebyincreasing the expandability of the cuff body when disposed around anerve. In one embodiment, the cuff body comprises first and secondregions opposite to each other, wherein the thicker portion isincorporated into the first region, and the thinner portion isincorporated into the second region, such that the thinner portion isconfigured for overlapping the thicker portion when the cuff body isdisposed around the nerve. The electrode contact(s) may be affixed tothe second region of the cuff body.

In accordance with a fifth aspect of the present invention, the cuffbody comprises first and second opposing regions, and a serpentine strapextending from the first region cuff body. The strap is configured forbeing affixed to the second region of the cuff body, thereby increasingthe expandability of the cuff body when disposed around a nerve.

In accordance with a sixth aspect of the present inventions, the cuffbody comprises one or both of cutouts or slits, thereby increasing theexpandability of the cuff body when disposed around a nerve, and a thinstretchable film affixed to the cuff body over cutouts and/or slits. Thecutouts and/or slits may have arranged in the manner described above.The thin stretchable film may, e.g., be composed of silicone. The cuffbody may have a thickness less than 1 mm, and the thin stretchable filmmay have a thickness less than 0.5 mm, and perhaps less than 0.1 mm.

Other and further aspects and features of the invention will be evidentfrom reading the following detailed description of the preferredembodiments, which are intended to illustrate, not limit, the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of preferred embodimentsof the present invention, in which similar elements are referred to bycommon reference numerals. In order to better appreciate how theabove-recited and other advantages and objects of the present inventionsare obtained, a more particular description of the present inventionsbriefly described above will be rendered by reference to specificembodiments thereof, which are illustrated in the accompanying drawings.Understanding that these drawings depict only typical embodiments of theinvention and are not therefore to be considered limiting of its scope,the invention will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1 is a perspective view of an electrode lead with a nerve cuffelectrode constructed in accordance with one embodiment of the presentinventions;

FIG. 2 is a plan view of one embodiment of the cuff electrode of theelectrode lead of FIG. 1 , which can be rolled up and circumferentiallydisposed around a nerve;

FIG. 3 is a cross-sectional view of the cuff electrode of FIG. 2 , takenalong the line 3-3;

FIG. 4 a is a perspective view of one embodiment of the cuff electrodeof the electrode lead of FIG. 1 , particularly shown in a rolled up,relaxed state;

FIG. 4 b is a perspective view of the cuff electrode of FIG. 4 a ,particularly shown in a rolled up, expanded state;

FIG. 5 a is a plan view of the cuff electrode of FIG. 4 a in an unrolledform and in the absence of a tensile force;

FIG. 5 b is a plan view of the cuff electrode of FIG. 4 b in an unrolledform and in the presence of a tensile force;

FIG. 6 a is a cross-sectional view of the cuff electrode of FIG. 5 a ,taken along the line 6 a-6 a;

FIG. 6 b is a cross-sectional view of the cuff electrode of FIG. 5 b ,taken along the line 6 b-6 b;

FIG. 7 a is a plan view of a relaxed strut of the cuff electrode of FIG.4 a;

FIG. 7 b is a plan view of a stretched strut of the cuff electrode ofFIG. 4 b;

FIG. 8 a is a plan view of an alternative embodiment of the cuffelectrode of FIG. 4 a in an unrolled form and in the absence of atensile force;

FIG. 8 b is a plan view of an alternative embodiment of the cuffelectrode of FIG. 4 b in an unrolled form and in the presence of atensile force;

FIG. 9 a is a cross-sectional view of the cuff electrode of FIG. 8 a ,taken along the line 9 a-9 a;

FIG. 9 b is a cross-sectional view of the cuff electrode of FIG. 8 b ,taken along the line 9 b-9 b;

FIG. 10 a is a perspective view of another embodiment of the cuffelectrode of the electrode lead of FIG. 1 , particularly shown in arolled up, relaxed state;

FIG. 10 b is a perspective view of the cuff electrode of FIG. 10 a ,particularly shown in a rolled up, expanded state;

FIG. 11 a is a plan view of the cuff electrode of FIG. 10 a in anunrolled form and in the absence of a tensile force;

FIG. 11 b is a plan view of the cuff electrode of FIG. 10 b in anunrolled form and in the presence of a tensile force;

FIG. 12 a is a cross-sectional view of the cuff electrode of FIG. 11 a ,taken along the line 12 a-12 a;

FIG. 12 b is a cross-sectional view of the cuff electrode of FIG. 11 b ,taken along the line 12 b-12 b;

FIG. 13 a is a plan view of a relaxed strut of the cuff electrode ofFIG. 10 a;

FIG. 13 b is a plan view of a stretched strut of the cuff electrode ofFIG. 10 b;

FIG. 14 a is a plan view of an alternative embodiment of the cuffelectrode of FIG. 10 a in an unrolled form and in the absence of atensile force;

FIG. 14 b is a plan view of the relaxed cuff electrode of FIG. 10 b inan unrolled form and in the presence of a tensile force;

FIG. 15 a is a cross-sectional view of the cuff electrode of FIG. 14 a ,taken along the line 15 a-15 a;

FIG. 15 b is a cross-sectional view of the cuff electrode of FIG. 14 b ,taken along the line 15 b-15 b;

FIG. 16 a is a perspective view of still another embodiment of the cuffelectrode of the electrode lead of FIG. 1 , particularly shown in arolled-up, relaxed state;

FIG. 16 b is a perspective view of the cuff electrode of FIG. 16 a ,particularly shown in a rolled-up, expanded state;

FIG. 17 a is a plan view of the relaxed cuff electrode of FIG. 16 a inan unrolled form and in the absence of a tensile force;

FIG. 17 b is a plan view of the expanded cuff electrode of FIG. 16 b inan unrolled form and in the presence of a tensile force;

FIG. 18 a is a cross-sectional view of the cuff electrode of FIG. 17 a ,taken along the line 18 a-18 a;

FIG. 18 b is a cross-sectional view of the cuff electrode of FIG. 17 b ,taken along the line 18 b-18 b;

FIG. 19 a is a plan view of an alternative embodiment of the relaxedcuff electrode of FIG. 16 a in an unrolled form and in the absence of atensile force;

FIG. 19 b is a plan view of the relaxed cuff electrode of FIG. 16 b inan unrolled form and in the presence of a tensile force;

FIG. 20 a is a cross-sectional view of the cuff electrode of FIG. 19 a ,taken along the line 20 a-20 a;

FIG. 20 b is a cross-sectional view of the cuff electrode of FIG. 19 b ,taken along the line 20 b-20 b;

FIG. 21 a is a perspective view of yet another embodiment of the cuffelectrode of the electrode lead of FIG. 1 , particularly shown in arolled up, relaxed state;

FIG. 21 b is a perspective view of the cuff electrode of FIG. 21 a ,particularly shown in a rolled up, expanded state;

FIG. 22 a is a plan view of the relaxed cuff electrode of FIG. 21 a inan unrolled form and in the absence of a tensile force;

FIG. 22 b is a plan view of the expanded cuff electrode of FIG. 21 b inan unrolled form and in the presence of a tensile force;

FIG. 23 a is a cross-sectional view of the cuff electrode of FIG. 22 a ,taken along the line 23 a-23 a;

FIG. 23 b is a cross-sectional view of the cuff electrode of FIG. 22 b ,taken along the line 23 b-23 b;

FIG. 24 a is a plan view of an alternative embodiment of the relaxedcuff electrode of FIG. 21 a in an unrolled form and in the absence of atensile force;

FIG. 24 b is a plan view of an alternative embodiment of the relaxedcuff electrode of FIG. 21 b in an unrolled form and in the presence of atensile force;

FIG. 25 a is a cross-sectional view of the cuff electrode of FIG. 24 a ,taken along the line 25 a-25 a;

FIG. 25 b is a cross-sectional view of the cuff electrode of FIG. 24 b ,taken along the line 25 b-25 b;

FIG. 26 a is a perspective view of yet another embodiment of the cuffelectrode of the electrode lead of FIG. 1 , particularly shown in arolled up, relaxed state;

FIG. 26 b is a perspective view of the cuff electrode of FIG. 26 a ,particularly shown in a rolled up, expanded state;

FIG. 27 a is a plan view of the relaxed cuff electrode of FIG. 26 a inan unrolled form;

FIG. 27 b is a plan view of the expanded cuff electrode of FIG. 26 b inan unrolled form;

FIG. 28 a is a cross-sectional view of the cuff electrode of FIG. 26 a ,taken along the line 28 a-28 a;

FIG. 28 b is a cross-sectional view of the cuff electrode of FIG. 26 b ,taken along the line 28 b-28 b;

FIG. 29 a is a perspective view of yet another embodiment of the cuffelectrode of the electrode lead of FIG. 1 , particularly shown in arolled up, relaxed state;

FIG. 29 b is a perspective view of the cuff electrode of FIG. 29 a ,particularly shown in a rolled-up, expanded state;

FIG. 30 a is a plan view of the relaxed cuff electrode of FIG. 29 a inan unrolled form and in the absence of a tensile force;

FIG. 30 b is a plan view of the expanded cuff electrode of FIG. 29 b inan unrolled form and in the presence of a tensile force;

FIG. 31 a is a cross-sectional view of the cuff electrode of FIG. 29 a ,taken along the line 31 a-31 a;

FIG. 31 b is a cross-sectional view of the cuff electrode of FIG. 29 b ,taken along the line 31 b-31 b;

FIG. 32 a is a perspective view of yet another embodiment of the cuffelectrode of the electrode lead of FIG. 1 , particularly shown in arolled-up, relaxed state;

FIG. 32 b is a perspective view of the cuff electrode of FIG. 32 a ,particularly shown in a rolled-up, expanded state;

FIG. 33 a is a plan view of the relaxed cuff electrode of FIG. 32 a inan unrolled form and in the absence of a tensile force;

FIG. 33 b is a plan view of the expanded cuff electrode of FIG. 32 b inan unrolled form and in the presence of a tensile force;

FIG. 34 a is a cross-sectional view of the cuff electrode of FIG. 32 a ,taken along the line 34 a-34 a; and

FIG. 34 b is a cross-sectional view of the cuff electrode of FIG. 32 b ,taken along the line 34 b-34 b.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring first to FIGS. 1-3 , an electrode lead 10 constructed inaccordance with one embodiment will now be described. Although theelectrode lead 10 lends itself well to be used in the treatment of OSAby stimulating the hypoglossal nerve, the electrode lead 10 may be usedfor any medical treatment where it is desired to stimulate a nerve.

The electrode lead 10 generally comprises an elongated lead body 12having a proximal end 14 and a distal end 16, at least one leadconnector terminal 18 (two shown) affixed to the proximal end 14 of thelead body 12, a cuff body 20 affixed to the distal end 16 of the leadbody 12, at least one electrode contact 22 (three shown) disposed on thecuff body 20, and at least one electrical conductor 24 (two shown)extending through the lead body between the lead connector terminals 18and the electrode contacts 22. As shown, the cuff body 20 can becircumferentially disposed around tissue, e.g., a nerve 26, such thatthe electrode contacts 22 are disposed on an inner surface of the cuffbody 20 in contact with the nerve 26.

In the illustrated embodiment, the electrode contacts 22 form a guardedtripolar electrode arrangement (e.g., anode-cathode-anode) that can beused for purposes of stimulating the nerve 26. Two of the electrodecontacts 22 (the anodes) are ganged together and coupled to one of thelead connector terminals 18 via an electrical conductor 24, and theremaining electrode contact 22 (the cathode) is coupled to the otherlead connector terminal 18 via the other electrical conductor 24. Itshould be appreciated that, alternatively, the number of electrodecontacts 22, lead connector terminals 18, and electrical conductors 24can be identical, such that electrode contacts 22 may be energizedindependently of each other.

The lead connector terminals 18 of the proximal end 14 of the lead body12 can be inserted into a connector block 30 of a neurostimulationdevice 28, which supplies electrical pulses to the electrode contacts 22in accordance with a stimulation regimen. Recording electrodes (notshown) can also be connected to the neurostimulation device 28 toprovide sensed physiological signals (e.g., electromyogram (EMG)signals) to the neurostimulation device 28. In an alternativeembodiment, the electrode contacts 22 of the electrode lead 10 can serveas recording electrodes to detect nerve action potentials.

The lead body 12 and cuff body 20 may be composed of an elastic,electrically insulative, biocompatible, material, such as, e.g.,medical-grade silicone, polyurethane, etc. The lead connector terminals18 may be composed of a suitable electrically conductive material, suchas, e.g., stainless steel, and the electrode contacts 22 may be composedof a suitable electrically conductive and biocompatible material, suchas gold, or 90/10 or 80/20 Platinum-Iridium alloy. The electricalconductors 24 may likewise be composed of a suitable electricallyconductive and biocompatible material, such as MP35N, MP35N with silvercore, stainless steel, or tantalum. The cuff body 20 may be relativelythin, e.g., having a thickness less than 1 mm, and in some cases lessthan 0.5 mm, so that the cuff body 20 may be easily disposed around inconformance with the nerve 26. The cuff body 20 may take the form of aplanar sheet, when unrolled (as best shown in FIG. 2 ), but in itsnatural state, rolls up on itself to be circumferentially disposedaround the nerve 26 (as best shown in FIG. 1 ). The cuff body 20 has anopposing first region 32 and a second region 34, which when the cuffbody 20 is rolled up on itself, may overlap each other. In oneembodiment, the cuff body 20 may comprise a strap and bucklearrangement, along with a locking mechanism, that secures the cuff body20 around the nerve 26, as described in U.S. Provisional PatentApplication Ser. No. 62/500,080, entitled “Nerve Cuff Electrode LockingMechanism,” which is expressly incorporated herein by reference.

More significant to the present inventions, and notwithstanding that thecuff body 20 may include features that secure it around the nerve 26,the cuff body 20 can include features that increases the expandabilityof the cuff body 20 when circumferentially disposed around the nerve 26,thereby better accommodating any swelling of the nerve 26, whileallowing the cuff body 20 to retract back to its original size when theswelling of the nerve 26 subsides.

To this end, and with reference to FIGS. 4-7 , one embodiment of a cuffbody 20 a comprises a plurality of cutouts 36 a that form a plurality ofstruts 38 a within the first region 32 of the cuff body 20 a. In theillustrated embodiment, the struts 38 a are chevron-shaped struts thatare alternately angled in opposite directions. Alternatively, thechevron-shaped struts 38 a are all angled in the same direction. In theabsence of the application of a tensile force F on the cuff body 20 a,each strut 38 a will be relaxed, as illustrated in FIGS. 5 a-7 a ,whereas each strut 38 a will stretch and tends towards straightening outin response to the application of a tensile force F along the wall ofthe cuff body 20 a, as illustrated in FIGS. 5 b-7 b . FIGS. 5 a and 5 bshow for illustrative purposes, the cuff body 20 a in an unrolledposition, and the relaxed and expanded states of the cuff wall withtension applied to the cuff wall and no tension. In actual use, the wallof the cuff body 20 a would be rolled up around a nerve and the radialoutward force on the cuff body 20 a provided by a swollen nerve would betranslated to cuff wall tension. Thus, if the cuff body 20 a is properlysized to the nerve 26, each strut 38 a will be relaxed (as shown in FIG.4 a ) when the nerve 26 around which the cuff body 20 a iscircumferentially disposed is not swollen, and each strut 38 a willstretch and tend to straighten out (as shown in FIG. 4 b ) when thenerve 26 around which the cuff body 20 a is circumferentially disposedis swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, each strut 38 a (FIGS. 5 a-7 a ) will be in a relaxed stateof the cuff body 20 a (FIG. 4 a ). In response to the outward radialforce applied to the cuff body 20 a by the swelling of the nerve 26,thereby generating a tensile force F, each strut 38 a may stretch (FIGS.5 b-7 b ), facilitating the transition of the cuff body 20 a from itsrelaxed state (FIG. 4 a ) to its stretched, expanded state (FIG. 4 b ).In response to the decrease in the outward radial force applied to thecuff body 20 a as the swelling of the nerve 26 subsides, therebydiminishing or completely removing the tensile force F, each strut 38 amay again relax (FIGS. 5 a-7 a ), facilitating the transition of thecuff body 20 a from its expanded state (FIG. 4 b ) back to its relaxedstate (FIG. 4 a ). Thus, it can be appreciated that the increase in theflexibility of the cuff body 20 a by the inclusion of the cutouts 36 aand use of struts 38 a prevents, or at least minimizes, the stranglingof the nerve 26 as it swells, thereby allowing sufficient flow of bloodand other nutrients to the nerve 26.

In an optional embodiment, the cuff body 20 may further comprise a thinstretchable film 40 affixed (e.g., via bonding) to the cuff body 20 aunderneath and completely covering the cutouts 36 a. The thinstretchable film 40 may be on the inner surface of the cuff body 20 awhen the cuff body 20 a is rolled up on itself. Although the thinstretchable film 40 may help limit the expansion of the cuff body 20 ain response to the swelling of the nerve 26, the thin stretchable film40 may also help to facilitate restoration of the cuff body 20 a back toits original relaxed state. Furthermore, the thin stretchable film 40prevents connective tissue from growing into or out of the cutouts 36 ain the cuff body 20 a. In addition, the film 40 blocking the openings ofthe cutouts 36 a prevents undesired shunting of electrical currentthrough the cutouts 36 a, which would cause an inefficiency instimulation.

Although the cutouts 36 a and corresponding struts 38 a are illustratedin FIGS. 4 a, 4 b, 5 a, and 5 b as being formed only in the first region32 of the cuff body 20 a, it should be appreciated that the cutouts 36 aand corresponding struts 38 a may be formed in the entirety of a cuffbody 20 b illustrated in FIGS. 8 and 9 . As in the case with the cuffbody 20 a illustrated in FIGS. 4-7 , in the absence of the applicationof a tensile force F on the cuff body 20 b, each strut 38 a will berelaxed, as illustrated in FIGS. 8 a and 9 a , whereas each strut 38 awill stretch and tends towards straightening out in response to theapplication of a tensile force F on the cuff body 20 b, as illustratedin FIGS. 8 b and 9 b . However, because there are three rows of cutouts36 a and corresponding struts 38 a in the cuff body 20 b, theexpandability of the cuff body 20 b is further increased relative to theexpandability of the cuff body 20 a. As with the embodiment illustratedin FIGS. 4-7 , a thin stretchable film 40 may be affixed (e.g., viabonding) to the cuff body 20 b underneath and completely covering thecutouts 36 a to provide the aforementioned advantages.

In an alternative embodiment illustrated in FIGS. 10-13 , a cuff body 20c comprises a plurality of cutouts 36 b that create a plurality ofU-shaped struts 38 b. Similar to the cuff body 20 a illustrated in FIGS.4-7 , in the absence of the application of a tensile force F on the cuffbody 20 c, each strut 38 b will be relaxed, as illustrated in FIGS. 11a-13 a , whereas each strut 38 b will stretch and tends towardsstraightening out in response to the application of a tensile force F onthe cuff body 20 c, as illustrated in FIGS. 11 b-13 b . Thus, if thecuff body 20 c is properly sized to the nerve 26, each strut 38 b willbe relaxed (as shown in FIG. 10 a ) when the nerve 26 around which thecuff body 20 c is circumferentially disposed is not swollen, and willstretch (as shown in FIG. 10 b ) when the nerve 26 around which the cuffbody 20 c is circumferentially disposed is swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, each strut 38 b may be at rest (FIGS. 11 a-13 a )corresponding to the relaxed state of the cuff body 20 c (FIG. 10 a ).In response to the outward radial force applied to the cuff body 20 c bythe swelling of the nerve 26, thereby generating a tensile force F, eachstrut 38 b may stretch (FIGS. 11 b-13 b ), facilitating the transitionof the cuff body 20 c from its relaxed state (FIG. 10 a ) to itsexpanded state (FIG. 10 b ). In response to the decrease in the outwardradial force applied to the cuff body 20 c as the swelling of the nerve26 subsides, thereby diminishing or completely removing the tensileforce F, each strut 38 b may again relax (FIGS. 11 a-13 a ),facilitating the transition of the cuff body 20 c from its expandedstate (FIG. 10 b ) back to its relaxed state (FIG. 10 a ). Thus, it canbe appreciated that the expandability of the cuff body 20 c by theinclusion of the cutouts 36 b prevents, or at least minimizes, thestrangling of the nerve 26 as it swells, thereby allowing sufficientflow of blood and other nutrients to the nerve 26. As with the cuff body20 a illustrated in FIGS. 4-7 , a thin stretchable film 40 may beaffixed (e.g., via bonding) to the cuff body 20 a underneath andcompletely covering the cutouts 36 c to provide the aforementionedadvantages.

Although the cutouts 36 b and corresponding struts 38 b are illustratedas being formed only in the first region 32 of the cuff body 20 c, itshould be appreciated that the cutouts 36 b and corresponding struts 38b may be formed in the entirety of a cuff body 20 d illustrated in FIGS.14 and 15 . As in the case with the cuff body 20 c illustrated in FIGS.10-13 , in the absence of the application of a tensile force F on thecuff body 20 d, each strut 38 b will be relaxed, as illustrated in FIGS.14 a and 15 a , whereas each strut 38 b will stretch and tends towardsstraightening out in response to the application of a tensile force F onthe cuff body 20 d, as illustrated in FIGS. 14 b and 15 b . However,because there are three rows of cutouts 36 b and corresponding struts 38b in the cuff body 20 b, the expandability of the cuff body 20 d isfurther increased relative to the expandability of the cuff body 20 c.As with the embodiment illustrated in FIGS. 10-13 , a thin stretchablefilm 40 may be affixed (e.g., via bonding) to the cuff body 20 funderneath and completely covering the slits 42 to provide theaforementioned advantages.

In another embodiment illustrated in FIGS. 16-18 , a cuff body 20 ecomprises a plurality of slits 42 within the first region 32 of the cuffbody 20 e. The plurality of slits 42 are divided into a first set ofslits 42 a (in this case, one) that extend from a first edge 44 atowards a center of the cuff body 20 e, and a second set of slits 42 b(in this case, one) that extend from a second edge 44 b towards thecenter of the cuff body 20 e. The sets of slits 42 a, 42 b can bestaggered in an alternating fashion relative each other, such that theslits 42 a, 42 b can extend past a centerline 48 between the first andsecond edge 44 a, 44 b of the cuff body 20 e, thereby maximizing theexpandability of the cuff body 20 e. The cuff body 20 e furthercomprises a plurality of circular relief cutouts 46 disposed at the endsof the slits 42 a, 42 b opposite the respective first and second edges44 a, 44 b from which the slits 42 a, 42 b extend. In this manner,expansion of the cuff body 20 e will not cause shear forces at the endsof the slits 38 a, 38 b, which may otherwise rip or tear the cuff body20 e.

In the absence of the application of a tensile force F on the cuff body20 e, each slit 42 will be closed, as illustrated in FIGS. 17 a and 18 a, whereas each slit 42 will be open and stretched in response to theapplication of a tensile force F on the cuff body 20 e, as illustratedin FIGS. 17 b and 18 b . Thus, if the cuff body 20 e is properly sizedto the nerve 26, each slit 42 will close (as shown in FIG. 16 a ) whenthe nerve 26 around which the cuff body 20 e is circumferentiallydisposed is not swollen, and each slit 42 will open and stretch (asshown in FIG. 16 b ) when the nerve 26 around which the cuff body 20 eis circumferentially disposed is swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, each slit 42 may be closed (FIGS. 17 a and 18 a )corresponding to the relaxed state of the cuff body 20 e (FIG. 16 a ).In response to the outward radial force applied to the cuff body 20 e bythe swelling of the nerve 26, thereby generating a tensile force F, eachslit 42 may be open and stretched (FIGS. 17 b and 18 b ), facilitatingthe transition of the cuff body 20 e from its relaxed state (FIG. 16 a )to its expanded state (FIG. 16 b ). In response to the decrease in theoutward radial force applied to the cuff body 20 e as the swelling ofthe nerve 26 subsides, thereby diminishing or completely removing thetensile force F, each slit 42 may again close (FIGS. 17 a and 18 a ),facilitating the transition of the cuff body 20 e from its expandedstate (FIG. 16 b ) back to its relaxed state (FIG. 16 a ). Thus, it canbe appreciated that the increase in the expandability of the cuff body20 e by the inclusion of the slits 42 prevents, or at least minimizes,the strangling of the nerve 26 as it swells, thereby allowing sufficientflow of blood and other nutrients to the nerve 26. As with the cuff body20 a illustrated in FIGS. 4-7 , a thin stretchable film 40 may beaffixed (e.g., via bonding) to the cuff body 20 e underneath andcompletely covering the slits 42 to provide the aforementionedadvantages.

Although the slits 42 are illustrated as being formed only in the firstregion 32 of the cuff body 20 e, it should be appreciated that the slits42 may be formed in the entirety of a cuff body 20 f illustrated inFIGS. 19 and 20 . As in the case with the cuff body 20 e illustrated inFIGS. 16-18 , in the absence of the application of a tensile force F onthe cuff body 20 f, each slit 42 will be closed, as illustrated in FIGS.19 a and 20 a , whereas each slit 42 will open and stretch in responseto the application of a tensile force F on the cuff body 20 f, asillustrated in FIGS. 19 b and 20 b . However, because there are sevenslits 42, instead of just two, the expandability of the cuff body 20 fis further increased relative to the expandability of the cuff body 20e. As with the embodiment illustrated in FIGS. 16-18 , a thinstretchable film 40 may be affixed (e.g., via bonding) to the cuff body20 f underneath and completely covering the slits 42 to provide theaforementioned advantages.

In another embodiment illustrated in FIGS. 21-23 , a cuff body 20 gcomprises a plurality of slits 42 divided into a first set of slits 42 a(in this case, two) that extend from a first edge 44 a towards thecenter of the cuff body 20 g, a second set of slits 42 b (in this case,two) that extend from a second edge 44 b towards the center of the cuffbody 20 g, and a third set of slits 42 c that extend through thecenterline 48 of the cuff body 20 g, but do not extend to the first andsecond edges 44 a, 44 b. Rather than being staggered relative to eachother in an alternating fashion like the slits 42 a, 42 b in the cuffbody 20 e of FIGS. 16-18 , which extend past the centerline 48 of thecuff body 20 e, the slits 42 a, 42 b in the cuff body 20 g of FIGS.21-23 are aligned with each other, and do not extend past the centerline48 of the cuff body 20 g. The third set of slits 42 c do not extend tothe first and second edges 44 a, 44 b, and can be staggered relative tothe first and second sets of slits 42 a, 42 b in an alternating fashion.Similar to the embodiment illustrated in FIGS. 16-18 , the cuff body 20g may further comprise a plurality of circular relief cutouts 46disposed at the ends of the slits 42 a, 42 b opposite the respectivefirst and second edge 44 a, 44 b from which the slits 42 a, 42 b extend,and both ends of the slits 42 c.

When there is no tensile force F on the cuff body 20 g, each slit 42will be closed, as illustrated in FIGS. 22 a and 23 a , whereas eachslit 42 will be open and stretched in response to the application of atensile force F on the cuff body 20 g, as illustrated in FIGS. 22 b and23 b . Thus, if the cuff body 20 g is properly sized to the nerve 26,each slit 42 will close (as shown in FIG. 21 a ) when the nerve 26around which the cuff body 20 g is circumferentially disposed is notswollen, and will open and stretch (as shown in FIG. 21 b ) when thenerve 26 around which the cuff body 20 g is circumferentially disposedis swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, each slit 42 may be closed (FIGS. 22 a and 23 a )corresponding to the relaxed state of the cuff body 20 g (FIG. 21 a ).In response to the outward radial force applied to the cuff body 20 e bythe swelling of the nerve 26, thereby generating a tensile force F, eachslit 42 may be open and stretched (FIGS. 22 b and 23 b ), facilitatingthe transition of the cuff body 20 g from its relaxed state (FIG. 21 a )to its expanded state (FIG. 21 b ). In response to the decrease in theoutward radial force applied to the cuff body 20 g as the swelling ofthe nerve 26 subsides, thereby diminishing or completely removing thetensile force F, each slit 42 may again close (FIGS. 22 a and 23 a ),facilitating the transition of the cuff body 20 g from its expandedstate (FIG. 21 b ) back to its relaxed state (FIG. 21 a ). Thus, it canbe appreciated that the increase in the expandability of the cuff body20 g by the inclusion of the slits 42 prevents, or at least minimizes,the strangling of the nerve 26 as it swells, thereby allowing sufficientflow of blood and other nutrients to the nerve 26. As with the cuff body20 a illustrated in FIGS. 16-18 , a thin stretchable film 40 may beaffixed (e.g., via bonding) to the cuff body 20 g underneath andcompletely covering the slits 42 to provide the aforementionedadvantages.

Although the slits 42 are illustrated as being formed only in the firstregion 32 of the cuff body 20 g, it should be appreciated that the slits42 may be formed in the entirety of a cuff body 20 h illustrated inFIGS. 24 and 25 . As in the case with the cuff body 20 g illustrated inFIGS. 21-23 , when there is no tensile force F on the cuff body 20 h,each slit 42 will be closed, as illustrated in FIGS. 24 a and 25 a ,whereas each slit 42 will open and stretch in response to theapplication of a tensile force F on the cuff body 20 h, as illustratedin FIGS. 24 b and 25 b . However, because there are many more slits, theexpandability of the cuff body 20 h is further increased relative to theexpandability of the cuff body 20 g. As with the embodiment illustratedin FIGS. 21-23 , a thin stretchable film 40 may be affixed (e.g., viabonding) to the cuff body 20 h underneath and completely covering theslits 42 to provide the aforementioned advantages.

In another embodiment illustrated in FIGS. 26-28 , a cuff body 20 icomprises a wrinkled portion 50 a incorporated into the first region 32of the cuff body 20 i and an unwrinkled portion 50 b incorporated intothe second region 34 of the cuff body 20 i. In the illustratedembodiment, the wrinkled portion 50 a and the unwrinkled portion 50 bhave the same thickness.

In the absence of the application of a tensile force F on the cuff body20 i, the wrinkled portion 50 a will be furrowed, as illustrated inFIGS. 27 a and 28 a , whereas the wrinkled portion 50 a will be lessfurrowed and stretch in response to the application of a tensile force Fon the cuff body 20 i, as illustrated in FIGS. 27 b and 28 b . Thus, ifthe cuff body 20 i is properly sized to the nerve 26, the wrinkledportion 50 a will be more furrowed and contract (as shown in FIG. 26 a )when the nerve 26 around which the cuff body 20 i is circumferentiallydisposed is not swollen, and will be less furrowed and stretch (as shownin FIG. 26 b ) when the nerve 26 around which the cuff body 20 i iscircumferentially disposed is swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, the wrinkled portion 50 a may become more furrowed andcontract (FIGS. 27 a and 28 a ) corresponding to the relaxed state ofthe cuff body 20 i (FIG. 26 a ). In response to the outward radial forceapplied to the cuff body 20 i by the swelling of the nerve 26, therebygenerating a tensile force F, the wrinkled portion 50 a will become lessfurrowed and stretch (FIGS. 27 b and 28 b ), facilitating the transitionof the cuff body 20 i from its relaxed state (FIG. 26 a ) to itsexpanded state (FIG. 26 b ). In response to the decrease in the outwardradial force applied to the cuff body 20 i as the swelling of the nerve26 subsides, thereby diminishing or completely removing the tensileforce F, the wrinkled portion 50 a may again become more furrowed andcontract (FIGS. 27 a and 28 a ), facilitating the transition of the cuffbody 20 i from its expanded state (FIG. 26 b ) back to its relaxed state(FIG. 26 a ). Thus, it can be appreciated that the increase in theexpandability of the cuff body 20 i by the inclusion of the wrinkledportion 50 a prevents, or at least minimizes, the strangling of thenerve 26 as it swells, thereby allowing sufficient flow of blood andother nutrients to the nerve 26.

In another embodiment illustrated in FIGS. 29-31 , a cuff body 20 jcomprises a thinner stretchable portion 52 a incorporated into the firstregion 32 of the cuff body 20 j and a thicker portion 52 b incorporatedinto the second region 34 of the cuff body 20 j.

In the absence of the application of a tensile force F on the cuff body20 j, the stretchable portion 52 a will relax, as illustrated in FIGS.30 a and 31 a , whereas the stretchable portion 52 a will stretch inresponse to the application of a tensile force F on the cuff body 20 j,as illustrated in FIGS. 30 b and 31 b . Thus, if the cuff body 20 j isproperly sized to the nerve 26, the stretchable portion 52 a will relax(as shown in FIG. 29 a ) when the nerve 26 around which the cuff body 20j is circumferentially disposed is not swollen, and will stretch (asshown in FIG. 29 b ) when the nerve 26 around which the cuff body 20 jis circumferentially disposed is swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, the stretchable portion 52 a will be relaxed (FIGS. 30 aand 31 a ) corresponding to the relaxed state of the cuff body 20 j(FIG. 29 a ). In response to the outward radial force applied to thecuff body 20 j by the swelling of the nerve 26, thereby generating atensile force F, the stretchable portion 52 a will stretch (FIGS. 30 band 31 b ), facilitating the transition of the cuff body 20 j from itsrelaxed state (FIG. 29 a ) to its expanded state (FIG. 29 b ). Inresponse to the decrease in the outward radial force applied to the cuffbody 20 j as the swelling of the nerve 26 subsides, thereby diminishingor completely removing the tensile force F, the stretchable portion 52 amay again relax (FIGS. 30 a and 31 a), facilitating the transition ofthe cuff body 20 j from its expanded state (FIG. 29 b ) back to itsrelaxed state (FIG. 29 a ). Thus, it can be appreciated that theincrease in expandability of the cuff body 20 j by the inclusion of thestretchable portion 52 a prevents, or at least minimizes, the stranglingof the nerve 26 as it swells, thereby allowing sufficient flow of bloodand other nutrients to the nerve 26.

In another embodiment illustrated in FIGS. 32-34 , a cuff body 20 kcomprises a serpentine strap 54 extending from the first region 32 ofthe cuff body 20 k and configured for being affixed to the second region34 of the cuff body 20 k. When there is no tensile force F on the cuffbody 20 k, the serpentine strap 54 will relax, as illustrated in FIGS.33 a and 34 a , whereas the serpentine strap 54 will stretch in responseto the application of a tensile force F on the cuff body 20 k, asillustrated in FIGS. 33 b and 34 b . Thus, if the cuff body 20 k isproperly sized to the nerve 26, the serpentine strap 54 will relax (asshown in FIG. 32 a ) when the nerve 26 around which the cuff body 20 kis circumferentially disposed is not swollen, and will stretch (as shownin FIG. 32 b ) when the nerve 26 around which the cuff body 20 k iscircumferentially disposed is swollen.

That is, due to its elastomeric characteristics, when the nerve 26 isnot swollen, the serpentine strap 54 will be relaxed (FIGS. 33 a and 33a ) corresponding to the relaxed state of the cuff body 20 k (FIG. 32 a). In response to the outward radial force applied to the cuff body 20 kby the swelling of the nerve 26, thereby generating a tensile force F,the serpentine 54 will stretch (FIGS. 33 b and 34 b ), facilitating thetransition of the cuff body 20 k from its relaxed state (FIG. 32 a ) toits expanded state (FIG. 32 b ). In response to the decrease in theoutward radial force applied to the cuff body 20 k as the swelling ofthe nerve 26 subsides, thereby diminishing or completely removing thetensile force F, the serpentine strap 54 may again relax (FIGS. 33 a and34 a ), facilitating the transition of the cuff body 20 k from itsexpanded state (FIG. 32 b ) back to its relaxed state (FIG. 32 a ).Thus, it can be appreciated that the increase in the expandability ofthe cuff body 20 k by the inclusion of the serpentine strap 54 prevents,or at least minimizes, the strangling of the nerve 26 as it swells,thereby allowing sufficient flow of blood and other nutrients to thenerve 26.

Although particular embodiments of the present inventions have beenshown and described, it will be understood that it is not intended tolimit the present inventions to the preferred embodiments, and it willbe obvious to those skilled in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe present inventions. Thus, the present inventions are intended tocover alternatives, modifications, and equivalents, which may beincluded within the spirit and scope of the present inventions asdefined by the claims.

What is claimed is:
 1. An electrode lead, comprising: an elongated lead body having a proximal end and a distal end; at least one lead connector terminal affixed to the proximal end of the lead body; a biologically compatible, elastic, electrically insulative cuff body affixed to the distal end of the lead body, the cuff body configured for being circumferentially disposed around a nerve, the cuff body comprising first and second opposing regions and first and second opposing axially spaced circumferential edges when disposed around the nerve, a serpentine strap extending from the first region cuff body, the serpentine strap configured for being affixed to the second region of the cuff body, such that the serpentine strap alternately meanders toward and away from each of the first and second axially spaced circumferential edges when the cuff body is in a relaxed state when disposed around the nerve, the serpentine strap configured for becoming less serpentine in response to an increase in an outward radial force applied to the cuff body by a swelling of the nerve, thereby facilitating the transition of the cuff body from the relaxed state to an expanded state when disposed around the nerve; at least one electrode contact affixed to the cuff body; and at least one electrical conductor extending through the lead body between the at least one lead connector terminal and the at least one electrode contact.
 2. The electrode lead of claim 1, wherein the cuff body is composed of silicone.
 3. The electrode lead of claim 1, wherein the cuff body has a thickness less than 1 mm.
 4. The electrode lead of claim 1, wherein the at least one electrode contact is configured for being on an inner surface of the cuff body when disposed around the nerve.
 5. The electrode lead of claim 1, further comprising a locking feature configured for firmly securing the cuff body around the nerve.
 6. The electrode lead of claim 1, wherein the serpentine strap is configured for becoming more serpentine in response to a decrease in the outward radial force applied to the cuff body as the swelling of the nerve subsides, thereby facilitating the transition of the cuff body from the expanded state back to the relaxed state when disposed around the nerve.
 7. The electrode lead of claim 6, wherein, when the cuff body is configured for being circumferentially disposed around the nerve, the serpentine strap has a planar shape with a thickness extending along a radius of the nerve, and a width extending along a length of the nerve, the width being greater than the thickness, such that the width of the serpentine strap meanders between the axially spaced circumferential edges of the cuff body when the cuff body is in the relaxed state.
 8. The electrode lead of claim 7, wherein the thickness of the serpentine strap does not meander along a radius of the cuff body when the cuff body in the relaxed state.
 9. The electrode lead of claim 6, wherein the serpentine strap meanders between the first and second edges across a centerline of the serpentine strap between the first and second axially spaced circumferential edges. 